1. Field of the Invention
This invention relates to toothbrushes and, in particular to toothbrushes that are operated by the movement of a user's hand.
2. Information Disclosure Statement
The most effective way to maintain oral hygiene is by brushing the teeth. The toothbrush is widely accepted as the preferred device used to daily clean one's teeth. A quick glance at the large number of different types of toothbrushes available on the market today indicates that there are several divergent opinions as to what size, shape, material, and construction of toothbrush will maximize cleaning effectiveness. An example of one such patented toothbrush design is disclosed in U.S. Pat. 5,052,071 to Halm.
Regardless of the specific toothbrush design, toothbrushes operated by the user's hand include a generally rigid body made of plastic. One end of the body is called the head which holds the tufts or bristles for brushing and the other end serves as the handle. The user holds the handle and inserts the head of the toothbrush into the user's mouth and quickly and repetitively moves it back and forth applying lateral pressure against the teeth and/or gum at the same time. Since this is an everyday operation that people do all the time, brushing the teeth becomes automatic and very few people pay particular attention while brushing. People are typically rushed or in a hurry when brushing their teeth. Parents tell the children to hurry in the morning and remind them to be sure to brush their teeth. Children and adults hurriedly brush their teeth at least once, twice or even three times daily in their hectic daily routines. Often times, in the haste, both adults and children end up accidentally injuring themselves by ramming the hard rigid head of the toothbrush into their gum. Sometimes the result is bleeding of the gum which may continue to hurt for several days. Sores within the mouth hurt even more when eating because the salt and the spices tend to seek out the wound. Toothbrush mishaps of this nature occur to everybody sooner or later and occur with greater frequency to young children whose control of movement is somewhat unsteady. Thus, the problem is repeated again and again for millions of people.
An additional problem associated with oral hygiene and toothbrushes is that toothbrushes are not usually replaced regularly and thus are often times used significantly beyond their effective useful life. The dental profession has recommended toothbrush replacement after about three months of use, however, many people continue to use the same old worn out toothbrush for as long as a year. Efforts have been made in earnest to inform people to regularly replace their toothbrush, even to the extent of providing a toothbrush which changes in color to signal that it is time to replace the toothbrush.
U.S. Pat. No. 4,082,255 to Breuer et al. discloses a toothbrush having a colored region of filaments adapted to change in color intensity in response to increase use of the toothbrush to provide a signal indicating filament wear. While the '255 patent discloses a color signal to indicate that it is time to replace the toothbrush, this requires that the user understands that a change in color means that it's time to replace the toothbrush. However, it is also very possible that the user fails to replace the toothbrush since the color change is gradual over a period of time and/or the user fails to remember what the color change indicates, or the user does not replace the toothbrush because the appearance of the bristles may still appear fine even though the bristles have changed color. What is needed is a more positive reminder or indicator to the user to cause the user to replace the toothbrush regularly as recommended by the dental profession.
It is desirable to have a practical and useful toothbrush which effectively eliminates the self-inflicted injuries occurring while brushing one's teeth. It is desirable to have a toothbrush which is safe to use and inexpensive to manufacture. It is further desirable to have a toothbrush which actively informs the user that it is time to replace the worn out toothbrush. It is further desirable to have a toothbrush which effectively prevents extended usage beyond the effective life of the toothbrush.